The present invention relates to an energy ray-curable elastomer composition, more specifically to an energy ray-curable elastomer composition in which employing of an energy ray-curing system of an ene-thiol base makes it possible to increase the inter-crosslinking point molecular weight without changing the kind of an energy ray-curable compound before cured, preferably an oligomer and which provides an oligomer-cured substance having a braking elongation compatible with a processability.
Further, the present invention relates to a material for a gasket containing the energy ray-curable compound which provides a gasket enhancing a braking elongation without damaging a processability and other necessary physical properties and making it possible to inhibit cracking, breaking and the like from being caused, a gasket comprising a substance obtained by curing the above material for a gasket by an energy ray and a hard disk device prepared by using the above gasket.